1) Field of the Invention
The present invention relates to a method and apparatus for forming a steel container, to such steel container and a steel container preform therefore and further to a container provided at its open end with a dispensing unit or closure.
These containers may be used as pressure container for instance for dispensing aerosols, foodstuff such as dressings, sweet smelling gas mixtures and the like. The pressure in such a pressure container may range from 1-30 bar, in particular 10-20 bar. Such pressure containers are normally made from aluminum.
2) Brief Description of the Prior Art
Presently, there is a tendency for using steel instead of aluminum. The production of containers made of steel is problematic. For reasons that the container is to made starting from a steel cup or steel plate. The steel cup is to be formed in a container preform and provided with a curl and optionally a necked free end into which the curl is formed. Onto this curl a closure or dispensing unit is to clenched. All these manipulations starting from steel plate or a steel cup require that the metal is suitable for being subjected to forming operations resulting in a thinning of the wall of the steel cup and further radial expansion and reduction of diameter during the curling and/or necking operations.